接单工单支持置顶，抢单大厅优先展示

- 新增 work_orders.pinned_at 字段与迁移
- 管理端对已发布（待抢单）订单提供置顶/取消置顶操作，置顶订单带标记
- 抢单大厅按置顶时间优先排序，打手端卡片展示置顶标签

apps/backend/src/repositories/worker-platform/types.ts

@@ -177,6 +177,7 @@ export type WorkOrderRow = {
   sharing_total_quantity: number
   sharing_unit_reward: number
   published_at: string | null
+  pinned_at: string | null
   assigned_at: string | null
   submitted_at: string | null
   accepted_at: string | null
@@ -218,6 +219,8 @@ export type ListInput = {
   categoryId?: number
   workerSharingId?: number
   visibleAfterIso?: string
+  /** 置顶订单优先展示（抢单大厅使用） */
+  pinnedFirst?: boolean
   sort?: 'id_desc' | 'worker_claimed_at_desc'
 }
 

apps/backend/src/repositories/worker-platform/work-order-repo.ts

@@ -744,6 +744,7 @@ export async function listWorkOrders({
   categoryId = 0,
   workerSharingId = 0,
   visibleAfterIso = '',
+  pinnedFirst = false,
   sort = 'id_desc',
 }: ListInput = {}): Promise<{ items: WorkOrderRow[]; total: number }> {
   const effectiveStatuses =
@@ -786,11 +787,14 @@ export async function listWorkOrders({
           ) DESC NULLS LAST, wo.id DESC`
         })()
       : 'wo.id DESC'
+  const effectiveOrderBy = pinnedFirst
+    ? `wo.pinned_at DESC NULLS LAST, ${orderBy}`
+    : orderBy
   params.push(pageSize, offset)
   const itemsResult = await query<WorkOrderRow>(
     `${WORK_ORDER_SELECT}
      ${whereClause}
-     ORDER BY ${orderBy}
+     ORDER BY ${effectiveOrderBy}
      LIMIT $${params.length - 1} OFFSET $${params.length}`,
     params,
   )
@@ -813,6 +817,7 @@ export async function updateWorkOrder(
       | 'sharing_total_quantity'
       | 'sharing_unit_reward'
       | 'published_at'
+      | 'pinned_at'
       | 'assigned_at'
       | 'submitted_at'
       | 'accepted_at'
@@ -838,11 +843,12 @@ export async function updateWorkOrder(
         sharing_total_quantity = $9,
         sharing_unit_reward = $10,
         published_at = $11,
-        assigned_at = $12,
-        submitted_at = $13,
-        accepted_at = $14,
-        updated_at = $15
-      WHERE id = $16
+        pinned_at = $12,
+        assigned_at = $13,
+        submitted_at = $14,
+        accepted_at = $15,
+        updated_at = $16
+      WHERE id = $17
     `,
     [
       next.status,
@@ -856,6 +862,7 @@ export async function updateWorkOrder(
       toPositiveInteger(next.sharing_total_quantity, 1),
       toPositiveInteger(next.sharing_unit_reward, 0),
       next.published_at || null,
+      next.pinned_at || null,
       next.assigned_at || null,
       next.submitted_at || null,
       next.accepted_at || null,